Hello, welcome to just answer
I will post the directions and pictures here for you. These are directions for alternator belt or do you mean timing belt. Also for your information book time only pays 0.8 hour labor to replace belt. You shouldnt pay more than 50 to 70 dollars for this repair depending on where you live.
Loosen the adjuster lock bolt . . .
. . . then remove the alternator belt from the engine
Loosen the alternator support nut.
Loosen the adjuster lock bolt.
Rotate the adjuster bolt counter clockwise to release the tension on the belt.
Remove the belt.
Install the belt on the pulleys.
Rotate the adjuster bolt clockwise until the proper tension is reached.
Tighten the adjuster lock bolt and the alternator support nut.
Accessory V-belt routing-Mitsubishi 1.5L, 1.8L, 2.0L and 2.4L engines
Just in case you are referring to the timing belt I post them directions as well. However, I would recommend letting a qualified shop perform this repair of the timing belt.
Timing belt and related components-Lancer 2.0L engine
Remove the left side engine under cover. Disconnect the negative battery cable. Remove the engine mounting insulator.
Remove the crankshaft pulley.
Disconnect the crankshaft position sensor connection. Remove the timing belt front upper cover.
Disconnect the pressure hose clamp. Remove the power steering oil line bracket.
Remove the alternator adjusting brace. Remove the timing belt lower cover.
Remove the power steering pump bracket stay.
Remove the flange. Remove the engine support bracket.
Turn the crankshaft clockwise to align each timing mark and set the number one cylinder to TDC on the compression stroke. If the belt is going to be reused, mark the direction of rotation.
Loosen the tension pulley retaining bolt. Position a suitable tool against the tensioner pulley and pry it fully back in the direction of the arrow in the illustration. Temporarily tighten the tensioner pulley bolt.
Timing belt tensioner pulley and belt removal-Lancer 2.0L engine
Remove the timing belt. Remove the auto tensioner, tensioner pulley and tensioner arm
With the timing belt tensioner pulley bolt loosened, use a suitable tool and pry the tensioner pulley as close to the engine mount as possible. Temporarily tighten the tensioner bolt.
Align each of the crankshaft and camshaft sprocket timing marks.
Install the timing belt in the following order. Crankshaft sprocket, then water pump sprocket, then camshaft sprocket and finally tensioner pulley.
Timing belt sprocket alignment-Lancer 2.0L engine
Initially loosen the fixing bolt of the tensioner pulley fixed to the engine mount side by ¼ to ½ turn. Use the force of the tensioner spring to apply tension to the belt.
Turn the crankshaft in the clockwise direction for two rotations, and recheck to be sure that the timing marks on each sprocket are aligned.
After checking to be sure that no belt teeth in the section marked "A" in the illustration are lifted up and that the teeth in each sprocket are engaged, secure the tensioner pulley.
Timing belt teeth checking location-Lancer 2.0L engine
Install the flange.
Continue the installation in the reverse order of the re